What is PSSS?

The Puget Sound Seabird Survey (PSSS) is a citizen-science survey managed by Seattle Audubon that empowers volunteer birdwatchers to gather valuable data on wintering seabird populations in Puget Sound and the Strait of Juan de Fuca. Together, our team creates a snapshot of seabird density on more than 2,400 acres of nearshore saltwater habitat. It is the only land-based, multi-month survey in the Puget Sound region.

A recent analysis of seven years of bird observations by volunteer birdwatchers from Seattle Audubon Society’s Puget Sound Seabird Survey has found positive trends in several Puget Sound seabird species that had been in decline since the 1960s and 1970s.

The analysis focused on 18 seabird species that are indicators of Puget Sound environmental health at 62 survey locations from Whidbey Island to Olympia. The study found positive trends in occurrence of 14 species, including cormorants, grebes, sea ducks, loons, and alcids. However researchers cautioned that positive trends in sightings do not necessarily reflect increasing populations. For example, federally listed marbled murrelet populations continue to decline across Washington. The research also documented local hotspots for certain species, which may reflect especially important habitat or prey the birds depend on.

In addition, the study indicated that four species were in decline: white-winged scoter, brant, western grebe and red-necked grebe. These declines may result from geographical shifts or prey declines in Puget Sound or the Salish Sea, or environmental threats to their nesting grounds elsewhere. Similar citizen-science data from other areas have indicated that western grebes appear to have shifted to the south, out of the Puget Sound region.

The Puget Sound Seabird Survey monitors the presence of seabirds during winter months when many seabird species are most abundant around the Sound. More than 250 experienced volunteers have participated in the survey since its inception in 2007. At each survey location volunteers identify bird species and utilize distance sampling methods to collect data.

Survey Summary: 2016-17

The 2016-17 season of the Puget Sound Seabird Survey collected data from every one of the 121 active survey locations. A huge thank you to all 203 volunteers who took part this season (a project record!!), contributing over 1,300 hours of effort to the project. During the 825 surveys that took place from October 2016 to April 2017, 53 different species of seabird were recorded. For more detailed information, review the full 2016-17 survey report.

All surveys are synchronized to take place during a four hour window (determined by Seattle Audubon) on the first Saturday of the month, October through April. Each survey is 15-30 minutes in duration.

Using a ruler and a compass, surveyors gather data that allows scientists to estimate bird density through 'distance sampling'. Simply counting the number of birds in a given location is a simpler approach, but it forces scientists to assume that all birds are detected by observers. In reality, detection of any species declines with the distance from the observer: poor sighting conditions, quality of observing equipment, and observer inexperience all contribute to declining detection likelihood as distance increases. Distance sampling provides a robust approach to estimating density and allow for calculation of less biased density estimates.